Over the years, pigeons have become a common sight in American neighborhoods, parks and crowded urban areas. They have been called rats with wings as they live off discarded food and birdseed provided by humans. The typical blue-gray bird with dark wing bars is often seen in flocks with plain, spotted, pale, or rusty-red birds. They came to North America from Europe in the early 17 century. City pigeons nest on buildings and window ledges. In the countryside they also nest in barns and grain towers, under bridges and on natural cliffs. And while pigeons are common and have become a part of the American landscape, they’ve never been accused of being intelligent until now.

According to Ed Wasserman, professor of psychology at the University of Iowa and co-author of a new study, pigeons can categorize and name natural and artificial objects. The birds categorized 128 photographs into 16 categories. The findings of the study suggest a similarity between how pigeons learn the equivalent of words and the way children do.

“Unlike prior attempts to teach words to primates, dogs, and parrots, we used neither elaborate shaping methods nor social cues,” Wasserman says of the study, which appears online in the journal Cognition. “And our pigeons were trained on all 16 categories simultaneously, a much closer analog of how children learn words and categories.”

For Wasserman, who has been studying animal intelligence for decades, this latest finding is further proof that animals—whether primates, birds, or dogs—are smarter than once presumed and have more to teach scientists. “It is certainly no simple task to investigate animal cognition; But, as our methods have improved, so too have our understanding and appreciation of animal intelligence,” Wasserman says.

He goes on to add that, “Differences between humans and animals must indeed exist: many are already known. But, they may be outnumbered by similarities. Our research on categorization in pigeons suggests that those similarities may even extend to how children learn words.”